Mobile operating machines, such as concrete pumping machines for example, generally consist of a vehicle which has a front driving cab and a back frame, on which a work device is positioned, for example an articulated arm for pumping concrete.
The work device is moved by a movement turret, for example a rotatable turret on which the work device is positioned.
Moreover, these mobile operating machines generally require stabilizing legs, that is, at least a pair of front stabilizing legs and at least a pair of back stabilizing legs which, when necessary and during work operations, allow a stable support of the mobile operating machine on the ground.
Vertical hydraulic actuators are associated with the free and terminal ends of the front stabilizing legs and the back stabilizing legs, which allow to lift and stabilize the position of the entire mobile operating machine.
Normally, the front stabilizing legs comprise telescopic tubular elements that can be extended in a substantially horizontal direction, that is, parallel to the ground, while the back stabilizing legs are normally pivoted to the support structure, therefore they can be rotated, generally around an axis substantially perpendicular to the ground, with respect to the support structure, so as to be opened or closed.
The back stabilizing legs are normally disposed, in the inactive position, parallel to the longitudinal extension of the mobile operating machine and can be opened, if necessary, by rotation around rotation pins or suchlike, to be disposed in an active position and resting stably on the ground with said vertical hydraulic actuators.
On the contrary, the front stabilizing legs, with the extendable telescopic elements, pass from an inactive retracted position to an active elongated position, in which they rest stably on the ground by the activation of said vertical hydraulic actuators.
Normally, the front or back stabilizing legs are housed in, or connected to, support structures which are very heavy, bulky and which can require long assembly and mounting times on the mobile operating machine.
Moreover, the rotation points, or joints, of the back stabilizing legs and the extension or sliding zones of the front stabilizing legs with respect to the support structure do not normally allow an optimal distribution of the loads, both with regard to the back part of the support structure, and also with regard to the front part thereof.
In particular, it is known that the mechanical stresses induced on the front and back stabilizing legs are due, for the most part, to the distribution of weights and to the movements to which the work device, for example, the articulated arm, is subjected.
These mechanical stresses are very variable both due to movements of the articulated arm itself, and also due to movements of the rotatable turret to which the work device is connected.
It is also known that the movement turret is attached to the back frame of the operating machine, usually in a forward position, that is, toward the front driving cab of the vehicle. This disposition, in addition to increasing the bulk in length of the operating machine, also causes an imbalance in the distribution of loads between the pair of front stabilizing legs and the back ones.
The distribution of loads, therefore, is not homogeneous and uniform, and can generate imbalances on the mobile operating machine or different stresses between the front and back stabilizing legs.
Known support structures for stabilizing legs are also not very compact and rather bulky and, normally, also house some service systems of the operating machine itself, making it difficult to access, if any possible intervention is required, for example maintenance or other. One example of such service systems can be the oil tank, normally integrated into the support structure of the stabilizing legs.
US 2014/0246100 A1 describes a truck-mounted pump for delivering concrete in which there is a stabilization system equipped with extendable front legs and back legs articulated with respect to a pivoting point. This document does not provide details and characteristics of the pivoting positions of the back legs with respect to the structure that contains the front legs.
DE 20 2007 002 114 U1 describes a similar truck-mounted pump for delivering concrete in which the back stabilizing legs are pivoted on a bearing structure.
DE 100 32 622 A1 describes a truck-mounted pump equipped with four support legs in which at least the front legs are both telescopically extendable and rotatable with respect to a pivoting point.
CN 103158682 and WO 2015/198089 concern support structures for truck-mounted pumps equipped with four telescopically extendable legs.
Other limitations and disadvantages of conventional solutions and technologies will be clear to a person of skill after reading the remaining part of the present description with reference to the drawings and the description of the embodiments that follow, although it is clear that the description of the state of the art connected to the present description must not be considered an admission that what is described here is already known from the state of the prior art.
There is therefore a need to perfect a mobile operating machine which can overcome at least one of the disadvantages of the state of the art.
One purpose of the present invention is to provide a mobile operating machine which is provided, in particular, with a support structure for the stabilizing legs which allows a homogeneous and uniform distribution of the loads in all its parts and thus allows to prevent undesired imbalances and stresses on the machine.
Another purpose of the present invention is to provide a mobile operating machine which allows to optimize and simplify the allocation of spaces with regard to service systems, for example the oil tank.
Another purpose of the present invention is to provide a mobile operating machine which is equipped with a support structure for the stabilizing legs, which is compact and not bulky compared with known solutions, which is also easy to assemble, has low costs and is easy to access the various components, which, in any case, are advantageously fewer in number than what is required in known solutions.
Another purpose of the present invention is to provide a mobile operating machine which, thanks in particular to its compactness, allows simple and optimal maintenance and monitoring operations, compared with known articulated structures of greater complexity which therefore have greater difficulties in inspection, monitoring and maintenance.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.